Factors associated with continued employment among patients with rheumatoid arthritis: a survival model

To evaluate the association of demographic, disease, workplace, social, and household factors with the ability of patients with rheumatoid arthritis (RA) to remain employed over time.

Four hundred seventy-two employed patients with RA recruited from a national sample of rheumatology practices were followed. Patients were interviewed once a year by telephone for 9 years and patients' physicians provided data on clinical aspects such as disease stage, joint deformity, and flares. A proportional hazards survival model based on stepwise variable selection was developed to investigate the association between continuance of work over a 9 year period and demographic, work, attitudinal, disease, and social support variables.

In the univariate analysis, the significant factors associated with longer work survival were being younger, being self-employed, having a higher prestige occupation, working more hours per week, having higher education level, and missing fewer days of work during the baseline year. The final multivariate model included age, type of occupation and number of days missed from work as a time varying co-variate.

Ability to remain employed over the 9 year study was more strongly associated with age, work characteristics, and time lost from work than with disease factors. The underlying mechanisms related to occupational prestige as a predictor of work survival should be investigated in order to develop interventions to reduce the risk of work disability.